E-Thesis 244 views 61 downloads
The Development of Novel Coating Solutions for the Improvement of Pre/Post Heat Treatment Performance Properties of Carbon Steel Conveyance Tubes / JAMES GRANT
Swansea University Author: JAMES GRANT
DOI (Published version): 10.23889/SUthesis.66151
Abstract
Due to the normalisation process at the SR2 Mill in TATA Steel Corby, low carbon steel conveyance tubes generate an unwanted surface oxidation called scale. This is both detrimental to the yield loss and surface cosmetic appearance of the conveyance product. To inhibit this, a coating was designed t...
| Published: |
Swansea University, Wales, UK
2024
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| Institution: | Swansea University |
| Degree level: | Doctoral |
| Degree name: | EngD |
| Supervisor: | Das, A., and Owen, C. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa66151 |
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| Abstract: |
Due to the normalisation process at the SR2 Mill in TATA Steel Corby, low carbon steel conveyance tubes generate an unwanted surface oxidation called scale. This is both detrimental to the yield loss and surface cosmetic appearance of the conveyance product. To inhibit this, a coating was designed to be applied prior to the normalisation stage to protect the steel surface. The construction and use of a purpose-built controlled atmosphere furnace allowed coating trials to experience the 9% O2 in the SR2 mill. Samples were heat treated using a pre-set thermal cycle and metallurgically prepared for optical microscope and SEM analysis. After a wide scope of coatings trials, two solutions were determined to be effective in scale prevention and were optimised by observing the oxidation kinetics, thermomechanical and phase properties. The first coating, utilised Na5P3O10 in combination with an acrylic addition to produce an impermeable phosphate coating through sol-gel application. This solution reduced oxidation by 82.1% and surface roughness improved by 41.1%. Using Laser Flash Analysis and Differential Scanning Calorimetry, it was determined that the thermal conductivity of this coating was between 0.6-1.0W/mK which may affect thermal transfer. The second coating was a silicate-based solution which was a mullite material reinforced with ZrO2 for improved porosity traits. This solution reduced oxidation by 94.9% but increased surface roughness by 14.7%. An initial investigation of the untreated steel found that there was a clear point at 650°C where wüstite domination was prominent and that furnace atmospheres with <6% O2 caused the wüstite – magnetite ratio to reduce from 94% to 88%. |
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| Item Description: |
A selection of third party content is redacted or is partially redacted from this thesis due to copyright restrictions. |
| Keywords: |
Tube Production, Scale, Oxide-Inhibition Coatings, Silicates, Phosphates, Normalisation |
| College: |
Faculty of Science and Engineering |
| Funders: |
EPSRC , WEFO , M2A |